Pelago loses CTO and co-founder Darren Vengroff

Darren Vengroff, who was co-founder and CTO at Pelago, the start-up behind Whrrl, a location-based social networking service, has joined a new company called richrelevance as Chief Scientist.

In his CTO role Darren Vengroff was the engineering brain behind Pelago and co-author of three patents hold by the company. Darren Vengroff left his role at Pelago in August and joined richrelevance in October.

Pelago core feature is to mix local search and social networking, allowing users to refine a local search in using ratings from friends and people that share the same interests. Pelago expects to monetize this free service (available on the iPhone and some others devices) by selling targeted advertisements and consumer behavior databases.

Pelago was created in early 2006 by Vengroff and Jeff Holden (CEO), both former employees of Amazon, and raised $22.4 million in two rounds of financing. Current investors include T-Mobile Venture Fund, Reliance Technology Ventures of India, DAG Ventures, Kleiner Perkins Caufield & Byer (KPCB), Trilogy Equity Partners and Bezos Expeditions.